node-red-contrib-iota-tx0/tx0Publish.js

## Requirements

const IOTA = require('iota.lib.js');
const TRAN = require('transliteration');

module.exports = function(RED) {
    function tx0Publish(config) {
        RED.nodes.createNode(this,config);
        var node = this;
        node._sec = 2;
	node._firstroot = '';
        
	console.log("Publish 0-value tx on iota node: " + config.iotaNode);
        
	const iota = new IOTA({ provider: config.iotaNode })
        node.readyIota = true;

        node.on('input', function(msg) {
            if (this.readyIota) {
              let txt = JSON.stringify(msg.payload);
	      let ascii = TRAN.transliterate(txt)
              let trytes = iota.utils.toTrytes(ascii)
              
              console.log("message payload: "+msg.payload)
	      console.log("transliterated: "+ascii)
              console.log("trytes: "+trytes)

              console.log("Uploading dataset via sendTransfer - please wait")
	      const iota_addr = config.iotaAddr; //'HELLOWORLDHELLOWORLDHELLOWORLDHELLOWORLDHELLOWORLDHELLOWORLDHELLOWORLDHELLOWORLDD'
	      const iota_seed = config.iotaSeed; //'HELLOWORLDHELLOWORLDHELLOWORLDHELLOWORLDHELLOWORLDHELLOWORLDHELLOWORLDHELLOWORLDD'
	      const transfers = [
		  {
    			value: 0,
    			address: iota_addr,
    			message: trytes
  		  }
	      ]
              this.readyIota = false;
              var self = this;
              iota.api.sendTransfer(iota_seed, 14, 14, transfers, (error, success) => {
                console.log("Report from iota node:")
  		if (error) {
    	 	  console.log(error);
                  msg.payload=error ;
                  self.send(msg);
  		} else {
    		  console.log(success);
                  msg.payload=success;
                  self.send(msg);
  		}
                self.readyIota = true;
	      });
            }
        });
    }
    RED.nodes.registerType("tx0Publish",tx0Publish);
}